Defluorination process using activated carbon

Abstract

A method for preparing an unsaturated fluorocarbon by defluorinating a perfluoroalkane employing activated carbon.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows: 
     
       1. A process for preparing an unsaturated aliphatic or cycloaliphatic perfluorocarbon having at least six carbon atoms and having at least one carbon-carbon double bond comprising contacting the corresponding perfluoroalkane or perfluorocycloalkane having at least two adjacent tertiary carbon atoms with activated carbon at a temperature of from about 300° to about 500° C. to defluorinate said perfluoroalkane or perfluorocycloalkane, thereby forming the corresponding unsaturated aliphatic or cycloaliphatic perfluorocarbonn having at least one carbon-carbon double bond. 
     
     
       2. A process according to claim 1 wherein the perfluoroalkane or perfluorocycloalkane has from 6 to 14 carbon atoms. 
     
     
       3. A process according to claim 2 wherein the perfluoroalkane is perfluoro-2,3-dimethylbutane. 
     
     
       4. A process according to claim 2 wherein the perfluorocycloalkane is perfluoro-1,2-dimethylcyclobutane. 
     
     
       5. A process according to claim 2 wherein the perfluorocycloalkane is perfluorodecahydronaphthalene. 
     
     
       6. A process according to claim 2 wherein the perfluorocycloalkane is perfluorotetradecahydroanthracene. 
     
     
       7. A process according to claim 2 wherein the perfluorocycloalkane is perfluoro-1-methyldecahydronaphthalene. 
     
     
       8. A process according to claim 2 wherein the perfluorocycloalkane is perfluorotetradecahydrophenanthrene. 
     
     
       9. A process according to claim 1 wherein the temperature is from about 350° to about 450° C. 
     
     
       10. A process according to claim 9 wherein the activated carbon is in the form of granules.